LEDs Deliver More from Less in Car

LEDs Deliver More from Less article tells that LEDs continue to penetrate automotive lighting applications due to their long life and design flexibility.

LEDs continue to penetrate automotive lighting applications due to their long life and flexibility of use for body styling and interior design. LED lighting, used for the headlights, daytime running lights and turn signal indicators, allow for much greater design flexibility than that of either Xenon or incandescent light bulbs. This permits the body designers of an automobiles front end to do things that they could never do before.

The headlight itself has been the elusive goal of LED adoption in an automotive environment. The main reason for this has been the thermal design aspects of the LEDs and their associated driver circuits.
A high power, or high brightness LED’s light output has already exceeded the critical milestone of 100 lumens per Watt (lm/W) (15 lm/W for a typical 60W bulb).

LEDs Deliver More from Less article shows how a 25W white LED headlamp can be configured using an array of 18 LEDs in series with 350mA of current passing through them to produce the necessary light output. This kind of configuration can really live up to their promises and be effective headlamp.

Same can’t be said on the drop-on replacement products for normal light bulbs. My earlier LED car lights article shows how they do not live up to their promises and do not meet the regulations on car lights.

So if you want to have LED headlight on your car you need to have a new headlight design specifically designed for LEDs in mind.

20.1 Introduction
The majority of roads in North America and much of the rest of the world are not illuminated by fixed pole- mounted roadway lighting systems (NHTSA, 2007). Because of this, automotive lighting is a key component for driving safely at night.

The performance requirements for vehicle headlamps (such as those published in the United States as Federal Motor Vehicle Safety Standard 108) are based on standards and recommendations published by the Society of Automotive Engineers (SAE) and similar industry organizations. These requirements stipulate certain minimum or maximum luminous intensities toward different directions from the center of the vehicle lighting system.

A similar set of photometric performance requirements exists for countries outside North America; these differ in the particulars but have the same objectives of specifying luminous intensities to ensure vehicle lighting systems provide sufficient light for drivers to see at night while minimizing glare to other drivers, and to ensure that vehicle signal lights can be detected promptly and without ambiguity.

LED sources are substantially different from filament lamps used in most present-day automotive lighting applications in a number of important ways:

• LEDs have higher luminous efficacies (in lm/W) than filament sources, meaning they can produce higher intensities or broader beam patterns for the same amount of energy, or have a similar light output with lower energy requirements.

• The narrowband spectral output of colored LEDs produces a highly saturated color appearance, in contrast to broadband sources such as filament lamps, which require filters in order to produce colored illumination

• White phosphor- converted LEDs can be produced with a higher correlated color temperature (CCT) than filament lamps, which results in a more bluish color appearance.

• LEDs have very rapid onset and offset times: 10–20 ns, including the decay time of yttrium aluminum garnet (YAG) phosphors, compared to about 80–250 ms for filament lamps.
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it could be possible to obtain equivalent nighttime visual performance using LED sources that produce light levels that are 20% to 30% lower than those produced by filament lamps (Van Derlofske and Bullough, 2006).

The relatively high amount of short- wavelength spectral power in white LED illumination might also have some possible negative impacts for vehicle lighting, however.

More niche business for organic light emitting diodes, following Osram’s similar announcement with BMW.

Backing up its assertion that there will at least be niche markets for OLED lighting technology, Osram announced that a second automaker, Audi AG, is using the company’s OLED rear lights in a production model.

Munich-based Osram said Audi is using the Osram OLED rear light module in the Audi TT RS, a compact sports car.

Audi, part of Volkswagen group, introduced the car last spring, but Osram had not publicly stated that it is the supplier until now.

In July, Osram announced a similar agreement with German carmaker BMW, which is using the OLED taillights in the BMW M4 GTS high-performance coupe.

OLEDs — organic light-emitting diodes — are patches of material that emit light across their surface unlike LEDs, which are single points of light.

The Audi taillight houses 4 OLED panels, and the BMW has 15, all mounted inside a fitting.

“They do not cast any shadows and do not need any reflectors, light guides, or similar optics,” Osram said earlier this year. “OLED enables light sources to be designed in any shape and mounted on flexible carriers.”

OLEDs are becoming increasingly common in gadgets and as television screens. Some enthusiasts believe they will literally work their way into the fabric of clothing, bridges, and buildings, transforming things like fashion and architecture.

In 2017, Yole Développement estimates that the automotive lighting market should be close to $27.7 billion.

Automotive lighting growth is driven by natural LED cost erosion, increasing the LED penetration rate. Standardization of LED modules and their optimization are key factors behind decreasing costs. This has resulted in more vehicles equipped with LED technology.

synergies between automotive lighting technologies since the 1990s for various ADAS lighting functions

Since the first full LED headlamp was introduced in 2007, LED technology has gradually penetrated headlamp design. LED technology has allowed lighting to become a distinctive feature and enabled innovative functions like the glare-free adaptive high beam introduced in 2013. LED technology use had been limited to high-end vehicles and has had to compete with traditional light sources, namely halogen and high-intensity discharge (HID/Xenon). Improved LED performance, lower power consumption, and flexible design were the first enablers. Then, cost reductions helped LED technology spread to all vehicle categories.

Automotive lighting is driven by exterior lighting and especially headlamps, generating more than two-thirds of the total market revenue. Rear lighting is the second largest area, representing 17% of total market revenue. Interior lighting represents almost 10% of revenue but growth is expected to be linked to the development of autonomous vehicles and the creation of vehicles as “living homes.” Other types of lighting, such as fog lamps, CHMSL (Center High Mounted signal Lamps), or small lamps composed the remaining 7% of revenue in 2016.